Illuminant for incandescent lamps



A. DE LODYGUINE. ILLUMINANT FOR INGANDESGENT LAMPS (No Model.)

Patented Jan. 19, 1897.

ATTORNEYS.

UNITED STATES- PATENT 7 OFFICE.

ALEXANDER DE LODYGUINE, OF PITTSBURG, PENNSYLVANIA.

ILLUMINANT FOR INCANDESCENT LAMPS.

srncrrrcanon forming part of Letters Patent No. 575,668, dated January 19, 1897.

Application filed April 10, 1894.

To-all whom it may concern.-

Be it known that I, ALEXANDER DE LODY- GUINE, a citizen of Russia, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvementin Illuminants forlncandescent Lamps and Methods of Making Same, I

(Case No. 569,) of which thefollowing is a specification.

My invention relates to improvements in incandescent'electric lamps, and more partic- "larly to lamps of the type set forth in my nding application, Serial No. 457,227, filed anuary 4, 1893, wherein an all-metal illuminant is employed.

In the above-named application I have described a generic process for the manufacture of illuminants for incandescent lamps whereby the incandescing material is deposited upon a central fillet, which latter serves as a temporary support in manufacture, and not as a translating device for converting electric into actinic energy. In said application I have further described a specific series of steps whereby metallic chromium may be deposited upon a filletin the form of an illuminant.

The invention herein set forth is generically identical with that disclosed and claimed in the above-named application, but is specifically distinct therefrom in that it relates to a method or process whereby an illuminant may be produced by the deposit upon a fillet of a metal, one or more of whose gaseous chlorin compounds may be safely mixed with hydrogen, and upon application of heat to the mixture will be deposited'in metallic form therefrom.

My present invention also includes the illuminant for incandescent lamps composed of such a metal, and the metals which I have hitherto found best adapted for use in this process in the manufacture of this product are molybdenum and tungsten.

In the accompanying drawings, Figure 1 is a median section of an incandescent lamp containing my invention, and Fig. 2 is asection of the portion a: a: and y y of an illum1- nant made in accordance with myjnvention and showing the fillet within the same.

Although I have shown in the drawings this illuminant as used' in a stopper-lamp, itwill be understood that my invention relates to a Serial No. 5o'7,o 1o. (No specimens.)

I particular method for making illuminants and to a particular form of illuminant, irrespective of the kind of lamp wherein it is used.

As set forth in my above-named application, my invention contemplates the use of a conducting-fillet of a-nature capable of resisting heat and of supporting, at least temporarily, the metal of the illuminant without entering into chemical combination therewith. For this purpose I prefer a very fine platinum wire, the diameter of which shall be small with relation to the outside diameter of the illuminant to be formed thereon. In practice I have found a platinum fillet .001 of an inch in diameter to be suitable, although I have found it desirable to use even finer fillets in order to secure a higher resistance and a shorter illuminant for a given candle-power.

It will of course be understood that the dimensions above given for thefillet are only examples of those which may be used. The length and diameter of the fillet will of course depend upon the candle-power, watts percandle-power, and life of the lamp which it is desired to make. Upon this fillet a metal of high resistance and of a very refractory nature is deposited, and the process of deposition is continued until the proper size of illuminant is produced. proper current through the resulting structure a bright and lasting light is produced. So far the process herein described is identical with that set forth in my above-named. applicat on. In said application I set forth, among other things, that it was possible to use molybdenum and tungsten as illuminants by depositing them in this manner, and I further outlined two specific treatments whereby this might be accomplished. My presentinvent-ion relates to one of these treatments and contemplates the use of any highly-refractory metals whose gaseous chlorin compounds,

' upon mixture with hydrogen, deposit themselves in metallic form upon a heated surface.

The two metals named above belong to this category.

In depositing metals having the abovenamed chemical properties the following treatment is employed, and although the chlorids or chlorates of these metals may be used Upon passing a asthe gaseous compound from which upon mixture with hydrogen the metals may be deposited, I have found that the oxychlorids r v of molybdenum and tungsten possess advantages for use in this treatment which render them peculiarly valuable in this connection. \Vhile, therefore, leaving it to be distinctly understood that my invention contemplates the use of chlorids, chloratcs, or any other gaseous chlorin compounds of those metals which upon mixture with hydrogen deposit the metals themselves upon a heated surface, I shall proceed to describe my process in this case as carried out when the oxychlorids are used. In this branch of my process the oxychlorid is volatilized by heat and is brought into contact with the fillet in the presence of a stream of hydrogen. The fillet is heated by the passage of an electric current and the me tallic oxychlorid being 'red need by the hydrogen deposits the pure metal upon the surface of the fillet. This is continued until the illuminant has reached the proper thickness, which varies with the voltage and candlepower in practical use. In any case, however, the illuminant should be made thick enough to be self-supporting, and it should be remembered that the resistance of the deposited metal must be great enough to supply the heat necessary for its ownincandescence, as the fillet forms no part of the illuminant proper. The composition of the oxychlorid varies with the diiferent metals of this group, but the reduction by hydrogen and heat is accomplished whatever this composition may be.

In the case of molybdenum I prefer to carry out this generic process in the following specific manner: The formation of the oxychlorid is carried out by treatment of molybdic acid with hydrochloric acid in the presence of heat. The reaction occurring is: Moo -t- 2HOL=MOCL,O,H,O. The temperature employed should be from 150 to 200 ceuti grade. This treatment results iu the production of a heavy gaseous oxychlorid, which is permitted to fall upon the heated fillet, while at the same'time a current of hydrogen is caused to miugletherewith. Of course the mixture of the two gases may, if desired, be accomplished before they are conducted to the fillet, but I prefer in practice the former process. It will of course be remembered that owing to the great ditference in specific gravity between the oxychlorid gas and the hydrogen they will be better mingled by permitting the former to move downward in the mixing-chamber while the latter moves upward, the oxychlorid being admitted at the top of the chamber and the hydrogen at the bottom.

The fillet is heated at first to a temperature of from 800 to 1,000- centigrade, in order that the first layer of metal deposited from .the mixture may be caused to adhere intimately to the surface of the fillet. The color of the fillet at this point in the process should be a cherry color of considerable brilliancy. After the deposition commences I have found it best to cause a reduction of temperature by rheostatic means, reducing the temperature as the building up of the filament takes place.

The temperature during the greater part of this treatment and after the first few mo- 'ments shouldbeitbout 700 ccnt-igrade, or a red heat.

'lheoxychlorid of molybdenum is according to the following; formula: MoCL, 0,.1I,O+6H=IICL+3II,0+M0.

The apparatus whereby this process is carried out may be of any suitable description, it being understood that proper ordinary means are employed for leading the gases to the mixing-chamber for heating the same and for carrying ofi the waste products as fast as deposition takes place. herein claim any particular apparatus, as those skilled in chemistry will beable to carry out this process in many well-known ways. Of course it will be understood that the fillet is preferably heated by passing an electric current thcrethrough, but that any other meansof heating is appropriate which is consistent with the exclusion of foreign gases from the mixing-chamber and the fillet.

The particular metal employed for the illuminant is immaterial so long as one or more of its gaseous chlorin compounds, and particularly its oxychlorid, is capable of anon-explosive reduction by hydrogen and heat and so long as when reduced it is refractory enough to serve for a commercial incandescent lamp.

The particular substance employed for the fillet is immaterial so long as it is capable of being formed into a fine thread-like structure and does not form a compound with ,the superposed illuminant.

l. The method of forming illuminants for incandescent lamps which consists in imparting the desired shape to a conducting-fillet, immersing said fillet in a mixture of hydrogen and a gaseous chlorin compound of a refractory metal, and heating the fillet while so immersed, substantially as described.

2. The method of forming illuminants for incandescent lamps, which consists in imparting the desired shape to a conducting-fillet, immersingsaid fillet ina mixture of h ydrogen and a gaseous oxychlorid of refractory metal, and heating the fillet so immersed, substantially as described.

3. The method of forming illuminants for incandescent lamps which consists in imparting the desired shape to a conducting-fillet, immersing said fillet in amixture of hydrogen and a gaseous oxychlorid of a refractory metal, and passing an electric current through said fillet of suificient volume to heat the same to such a temperature as to cause the deposition of the metal from the gaseous mixture, substantially as described.

4. The method of forming illuminants for incandescent lam ps,-which consists in imparting the desired shape to a. conducting-fillet, immersing said fillet ina mixture of hydrogen and molybden um oxychlorid, and heating the fillet so immersed, substantially as described.

5. The method of forming illuminants for reduced I do not; therefore,

incandescent lamps which consists in imparting the desired shape to a conducting-fillet, passing gaseous hydrochloric acid over heated molybdic acid, mixing the gas so formed with 5 hydrogen, heating said fillet and immersing it in the mixture while hot, substantially as described.

6. An illuminant for electric lamps composed exclusively of an incandescing body of no molybdenum, substantially asdescribed.

7. An illuminant for electric lamps composed of an incandescing body of molybde num, and containing a platinum fillet, substantially as described. 'In testimony whereof I have hereunto subscribed my name this 26th day of March, A.

r A. m: LODYGUINE. Witnesses:

JAME$ WM. SMITH, HAROLD S. MACKAYE. 

